Prevalence of liver fibrosis by Fibroscan in patients on long-term methotrexate therapy for rheumatoid arthritis.

Abstract

Data on the long-term use of methotrexate (MTX) causing liver fibrosis in patients with rheumatoid arthritis (RA) is sparse. Liver biopsy is the gold standard to assess fibrosis but is an invasive procedure. Transient elastography (TE) by Fibroscan is a noninvasive validated tool to detect and quantify liver fibrosis. The present study aimed to assess the prevalence of liver fibrosis by Fibroscan in patients with RA on long-term MTX therapy and its correlation with cumulative dose of MTX. This cross-sectional study included adult patients (≥ 18 years age) of RA who had been on MTX for ≥ 3 years. The patients' records were reviewed, and the cumulative dose of MTX was calculated. Liver fibrosis was assessed by TE method, and the cutoff value of 7.1 kPa (kilopascal) was considered abnormal (liver fibrosis). Spearman's rank test was used to assess the correlation between the cumulative dose of MTX and Fibroscan score. Seventy-five patients were enrolled of which 69 were females (92%). The mean age was 47.2 ± 11.3 years. The mean body mass index and waist circumference were 24.8 ± 3.9 kg/m2 and 91.6 ± 9.9 cm, respectively. The median duration and cumulative dose of MTX were 336 weeks (interquartile range,144-912 weeks) and 6300 mg (interquartile range, 2400-22,000 mg), respectively. The mean liver stiffness was 5.22 ± 2.03 kPa. Twelve patients (16%) had Fibroscan score ≥ 7.1 kPa, of which 3 patients had severe liver stiffness (9.5 to 12.5 kPa) and one patient had liver stiffness in the range of cirrhosis (> 12.5 kPa). Fibroscan scores significantly correlated with cumulative dose of MTX (r= 0.30, p = 0.008). Long-term MTX therapy in RA was associated with increased liver stiffness on Fibroscan. Key Points • Fibroscan is a useful tool for monitoring MTX-induced liver fibrosis. • Liver fibrosis as evidenced by increased liver stiffness on Fibroscan is prevalent among patients on long-term MTX therapy for RA.